Answer
In The Da Vinci Code, the Priory of Sion is a secret society, founded A.D. 1099, claiming such members as Isaac Newton, Victor Hugo, and Leonardo Da Vinci. According to The Da Vinci Code, the primary purpose of the Priory of Sion is to maintain the truth that Jesus was married to Mary Magdalene and had children with her. These children then intermarried with the Merovingian line of Frankish kings, with the sacred bloodline surviving into modern times.
As with most of what is contained in The Da Vinci Code, there is very little, if any, evidence that would support these conclusions about the Priory of Sion. The Priory of Sion was founded in 1956, not 1099. The supposed ledgers of members of the Priory of Sion are considered to be fraudulent by most respected historians and scholars. The Da Vinci Code takes the Priory of Sion, attaches unfounded conspiracy theories about its origins and purposes, and uses it as evidence of a vast cover-up of Jesus’ marriage to Mary Magdalene.
Jesus was not married to Mary Magdalene or to anyone else. Jesus did not have children with Mary Magdalene or with anyone else. The early church did not seek to cover this up because there was nothing to cover up. The only conspiracy theory that involves the Priory of Sion is the one invented by author Dan Brown and others, who are using wild imaginations and unfounded theories to attack what the Bible says about who Jesus Christ truly was and what He came to earth to do.
